The primary function of this core is to provide all investigators of the SCOR with defined cell cultures, lipoproteins, and lipoprotein analysis. The cell culture core was established over 20 years ago and has been directed by Dr. Quehenberger since 1995. Over the years it has proved its value to each unit of the SCOR and has seen considerable expansion. With the demand for lipoproteins and analytical procedures for lipoproteins considerably rising, we decided to include these services into this core. The preparation of lipoproteins by trained personnel within one designated facility ensures preservation of quality. Moreover, the coordinate production based on demands is cost-effective and guarantees a continuous supply. Cell culture facility: This facility will provide all units with defined cells, all necessary cell culture supplies, equipment and culture techniques. The cell culture facility will facilitate the purchase and maintenance of established cell lines and will supply the investigators with cells with defined growth characteristics. On average, 10 different cell lines are growing at any given time. Cells are generally maintained in minimum quantities and are expanded only upon request. This prevents culturing of the same cell lines in the various units at the same time and helps keeping tissue culture costs at a minimum. The cell culture core also assists in preparing and establishing transfected cell lines. The participating investigators will supply the DNA constructs and the transfections are then done as a service in the cell culture facility. Various transfection reagents are being used depending on the cell type to be transfected. Adherent cells are commonly transfected with liposome-based reagents, while cells in suspension are usually electroporated. Screening and purification of the transfectants will be provided. The investigators will be responsible for the identification and confirmation of the clones. Transient transfections are being carried out upon request. Lipoprotein facility: This facility will provide the investigators of all units with lipoprotein preparations and will carry out all plasma lipid analyses. Lipoproteins (all classes) will be prepared on a biweekly basis or upon request. Healthy volunteers will be recruited and blood samples (50 -200 ml) will be drawn in the Lipid Research Clinic at UCSD by specially trained personnel under the supervision of Dr. Witztum. Lipoproteins will be prepared by density gradient centrifugation following standard protocols. The core facility will also provide lipoproteins including methylated, acetylated and oxidized lipoproteins as well as lipoprotein-deficient sera. The core facility also isolates and provides LDL from cholesterol-fed LDL receptor-deficient mice as well as guinea pigs. Core facility personnel will also prepare lipoproteins labeled with radionucleotides and fluorescent dyes.